Important People in the discovery of Electrons in Atoms:
-Dalton
-Thomson (plum-pudding)
-Rutherford
-Bohr (jumping from orbitals)
Scientists began to wonder why negativety charged eletrons never went crashing into the positvely charged nucleus (creating a collapse of the atom). They also started wondering where light came from. They also started wondering the properties of light:
-They thought it existed only as a wave
-Data came about which said that light was acctually a series of particles
-Energy levels are quantized - there has to be a specific number of engery
-Electrons release light when falling
-Photon/Quantum- "packet" of light Wave Nature of Light:
-Light is a kind of ellectromagnetic radiation (EMR), a form of energy that exists a wave-like behavior as it travels through space
-Caused by vibration of particles
Electromagnetic Spectrum
-All EMR have 4 Charicteristics
-Wavelength - The wavelength is the distance from the peak of one wave to the peak
of the next wave OR the distance from the "valley" of one wave to the "valley" of an other.
Represented by a λ (lambda) measured in meters (or some variation of).
-Frequency - The frequency of a wave is measured by the number of cycles (peaks) that pass a given point per second. Represented with the symbol μ(nu). Unit is measured in hertz (hz). I hz = s^-1 (cycles per second).
-Amplitude- The amplitude of a wave is a measure of the distance from the part of orgin. Deals with intensityy. High amplitude = More intence. Higher amplutidue is brighter than lower amplitude (dimmer).
-Speed/Velocity- All EMR have the exact same speed (the speed of light). 3.00 X 10^8 m/s (in a vaccum) represented by c. Because air is mostley empty space, the speed of light is only slightly slower. λ x μ = c and E= h x μ or E= h (c/ λ ) E= energy; h=Plank's constant (6.626 x 10^34)
Wavelength
Ampllitude
Light Characteristics:
Interferance Patterns
-certain materials reflect and absorb specific wavelengths of light
-this occurs because of the nature of the chemical bonds and their reactions to waves of a particular frequency
Double-Slit Experiment
-When light waves pass through a double slitted wall or screen, two new wave patterns begin. Light is only shown where the two patterns don't overlap, because otherwise it cancels out.
-after this experiment, it was determined light behaves as a wave because it follows the same patterns as other types of waves.
Double-Slit Experiment
Photoelectric Effect
-If light was only a wave, you could eject electrons by increasing the intensity of the waves, so light must also act as a particle because there is a certain amount of energy being released.
-after this experiment, it was determined Light can also be a particle because it shares the same characteristics of a particle.
Photoelectric Effect
Orbital Notation and Electron Configuration -The periodic table is organized in several different ways
1) Energy levels- there are 8
2) Sub-levels - s,p,d,f, and g
3) Variations of sub-levels - 1 variation of s, 3 of p, 5 of d, 7 of f, and 9 of g.
-each of these variations can hold 2 electrons
Orbital Notation:
-an orbital is represented by a box
-electrons are represented by arrows
Creating an orbital notation:
1)Figure out which type of orbitals are being filled
2)Draw the orbitals in order of increasing energy
3)Fill the electrons starting from the bottom *Hund's Rule-electrons spread out within an
energy level before paring up
Electron Configuration:
-shorthand form of orbital notation
Creating electron configurations:
1) list the sub-levels in order of increasing energy
with the number of valence electrons being the
exponent.
Example for Carbon: 1s^2, 2s^2, 2p^2
Example for Iron: 1s^2, 2s^2, 2p^6, 3s^2,
3p^6, 4s^2, 3d^6
Noble Gas Configuration:
-making this process even easier
Creating a noble gas configuration:
1) Start at the element needed, and move backwards
(or left) in the table until you reach a noble gas
2) Write down the noble gas in brackets
3) Finish the electron configuration resuming from the
noble gas
By: Lindsay Gibosn and Mariel Saldutte
Chapter 4- Electrons in Atoms
vocabulary - - main topics - - key equations
Important People in the discovery of Electrons in Atoms:
-Dalton
-Thomson (plum-pudding)
-Rutherford
-Bohr (jumping from orbitals)
Scientists began to wonder why negativety charged eletrons never went crashing into the positvely charged nucleus (creating a collapse of the atom). They also started wondering where light came from. They also started wondering the properties of light:
-They thought it existed only as a wave
-Data came about which said that light was acctually a series of particles
-Energy levels are quantized - there has to be a specific number of engery
-Electrons release light when falling
-Photon/Quantum- "packet" of light
Wave Nature of Light:
-Light is a kind of ellectromagnetic radiation (EMR), a form of energy that exists a wave-like behavior as it travels through space
-Caused by vibration of particles
Electromagnetic Spectrum
-All EMR have 4 Charicteristics
-Wavelength - The wavelength is the distance from the peak of one wave to the peak
of the next wave OR the distance from the "valley" of one wave to the "valley" of an other.
Represented by a λ (lambda) measured in meters (or some variation of).
-Frequency - The frequency of a wave is measured by the number of cycles (peaks) that pass a given point per second. Represented with the symbol μ(nu). Unit is measured in hertz (hz). I hz = s^-1 (cycles per second).
-Amplitude- The amplitude of a wave is a measure of the distance from the part of orgin. Deals with intensityy. High amplitude = More intence. Higher amplutidue is brighter than lower amplitude (dimmer).
-Speed/Velocity- All EMR have the exact same speed (the speed of light). 3.00 X 10^8 m/s (in a vaccum) represented by c. Because air is mostley empty space, the speed of light is only slightly slower.
λ x μ = c and E= h x μ or E= h (c/ λ )
E= energy; h=Plank's constant (6.626 x 10^34)
Light Characteristics:
Interferance Patterns
-certain materials reflect and absorb specific wavelengths of light
-this occurs because of the nature of the chemical bonds and their reactions to waves of a particular frequency
-When light waves pass through a double slitted wall or screen, two new wave patterns begin. Light is only shown where the two patterns don't overlap, because otherwise it cancels out.
-after this experiment, it was determined light behaves as a wave because it follows the same patterns as other types of waves.
-If light was only a wave, you could eject electrons by increasing the intensity of the waves, so light must also act as a particle because there is a certain amount of energy being released.
-after this experiment, it was determined Light can also be a particle because it shares the same characteristics of a particle.
Orbital Notation and Electron Configuration
-The periodic table is organized in several different ways
1) Energy levels- there are 8
2) Sub-levels - s,p,d,f, and g
3) Variations of sub-levels - 1 variation of s, 3 of p, 5 of d, 7 of f, and 9 of g.
-each of these variations can hold 2 electrons
-an orbital is represented by a box
-electrons are represented by arrows
Creating an orbital notation:
1)Figure out which type of orbitals are being filled
2)Draw the orbitals in order of increasing energy
3)Fill the electrons starting from the bottom
*Hund's Rule-electrons spread out within an
energy level before paring up
-shorthand form of orbital notation
Creating electron configurations:
1) list the sub-levels in order of increasing energy
with the number of valence electrons being the
exponent.
Example for Iron: 1s^2, 2s^2, 2p^6, 3s^2,
3p^6, 4s^2, 3d^6
-making this process even easier
Creating a noble gas configuration:
1) Start at the element needed, and move backwards
(or left) in the table until you reach a noble gas
2) Write down the noble gas in brackets
3) Finish the electron configuration resuming from the
noble gas
Example for Germanium: [Ar]4s^2, 3d^10,4p^2